Interfacing asterisk with outside lines

I have a general query for anyone who has successfully done this in the past,

I am at the point in system integration where I need to be able to interface to the outside world with my Asterisk box. I want to be able to utilise 10 lines on an ISDN on ramp service, I was looking at the specific digium hardware to do this with everything rolled into a rack-mountable box, however I do not want to go down this path. I want to keep the generic hardware that I have, whilst plugging some digium interface cards into the PCI /PCI-E slots in order to connect analog lines etc and facilitate the on ramp service.

What hardware is best for this and how much set up is involved in getting it to work? My current understanding is that i will have to uninstall asterisk and re-install when the hardware is plugged in so that it properly detects it, but past this I am completely un-aware of how to configure / use this hardware.